Apparatus and method for depositing synthetic fibers to form a nonwoven

ABSTRACT

The invention relates to an apparatus and a method for depositing synthetic fibers to form a nonwoven, in which the synthetic fibers are blown through a take-up nozzle as a fiber stream in a free space in the direction of a deposit belt. According to the invention, the fiber stream, before impinging onto the deposit belt, is guided by a guide segment formed between two guide members, one of the guide members being arranged on a belt exit side and an opposite guide members being arranged on a belt inlet side and forming, at a distance from the take-up nozzle, an open fiber entry gap for entry into the guide segment, and the guide segment extending as far as the deposit belt.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of International ApplicationNo. PCT/EP2006/010234, filed Oct. 24, 2006, and which designates theU.S. The disclosure of the referenced application is incorporated hereinby reference.

FIELD OF THE INVENTION

The invention relates to an apparatus for depositing synthetic fibers toform a nonwoven, and to a method for depositing a multiplicity of fibersto form a nonwoven.

BACKGROUND OF THE INVENTION

In the production of a nonwoven web consisting of synthetic fibers, amultiplicity of extruded filament strands have to be deposited asuniformly as possible to form a sheet-like structure. The filamentstrands are in this case taken up to a greater or lesser extent, afterextrusion and cooling, by a conveying fluid and are led to a depositbelt. In order to achieve conveying and depositing speeds which are ashigh as possible, methods and apparatuses have proven particularlyappropriate in which the take-up nozzle conveys the filament strandsinto an open system. A method of this type and an apparatus of this typeare known, for example, from U.S. Pat. No. 6,183,684. In this case, atake-up nozzle is used in order to take up the synthetic fibers, afterextrusion, from a spinning device, draft them and lay them down. Thetake-up nozzle has a guide duct which has a slit-shaped fiber inlet on atop side. Shortly below the fiber inlet, a plurality of fluid inletsissue into the guide duct, through which fluid inlets a conveying fluidis supplied to the guide duct under the action of an excess pressure. Asa result, the fiber strands are drawn into the take-up nozzle andaccelerated within the guide duct and are blown out as a fiber streamthrough the fiber outlet. At the same time, a drafting of the fiberstrands takes place, and these are subsequently received directly, fordepositing, by a deposit belt. In this case, the fibers impinge,together with the conveying fluid, as a fiber stream onto the depositbelt essentially perpendicularly. By means of such apparatuses andmethods, production speeds can be achieved at which the filament strandsmay reach speeds of up to 8000 m/min.

In order to influence the depositing of the synthetic fibers on thedeposit belt, it is known, furthermore, to arrange, in the free spaceformed between the take-up nozzle and the deposit belt, guide members bywhich the fiber flow can be varied in order to influence the depositingof the fibers. An apparatus of this type is known, for example, fromU.S. Patent Publication No. 2002/0158362 A1. The guide members are heldat a long distance from the deposit belt, in order to generate aswirling of air so as to give rise to a traversing movement of thefibers. Consequently, although special effects in the depositing of anonwoven can be achieved, these nevertheless increasingly lose theiraction at higher production speeds.

For the production of synthetic nonwoven webs, apparatuses and methodsare also known in which the take-up nozzles are connected directly tofollowing guide wells to form a closed system. An apparatus of this typeis known, for example, from DE 196 12 142 A1. In closed systems of thistype, the fiber stream generated by the take-up nozzle is conducteddirectly out of the fiber outlet into a guide well which guides thefiber stream until it is laid down on the deposit belt. However, closedsystems of this type have the fundamental disadvantage that, because ofthe guided flow, longer drafting zones and therefore greater distancesbetween the take-up nozzle and the deposit belt have to be maintained.Closed systems are therefore basically suitable only for low and mediumproduction or spinning speeds.

An object of the invention was to provide an apparatus and a method fordepositing synthetic fibers to form a nonwoven, of the generic type, inwhich uniform and controlled layings down of the fibers to form anonwoven are possible even at higher spinning speeds.

A further object of the invention is to improve an apparatus fordepositing synthetic fibers to form a nonwoven, to the effect that, onthe deposit belt, a nonwoven is generated which has an essentiallyconstant nonwoven thickness over the entire belt width.

SUMMARY OF THE INVENTION

These objects and others are achieved, according to the invention, bymeans of the apparatuses, and methods described and claimed below.

Advantageous developments of the invention are defined by the featuresand feature combinations of the claimed invention.

The invention possesses the advantage that the fibers can be guided,free of surrounding influences, in a protected space for depositing. Forthis purpose, the fiber stream generated by the take-up nozzle is blownout of the free space in an open fiber entry gap formed by the guidemembers, in order to be guided to the deposit belt within a guidesegment formed between the guide members. The guide members in this caseform a spatially delimited region above the deposit belt, in whichregion the fibers are deposited to form the nonwoven. It becameapparent, surprisingly, that the air swirling generated during thetransition of the fiber stream into the open fiber entry gap did nothave adverse effects on the depositing and the guidance of the fiberstream within the guide segment.

In order as far as possible to generate low swirls at the transition ofthe fiber stream out of the free space into the fiber entry gap, thedevelopment of the invention proved particularly appropriate in whichthe guide member arranged on the belt exit side is formed by a rotatablymounted roller which with the deposit belt forms a shaping gap for thenonwoven. In this case, both for the fiber inlet and for the depositingof the fibers, a favorable guide contour within the guide segment isprovided, by means of which a particularly advantageous depositing ofthe fiber on the deposit belt is achieved. On account of the rollercontour, the fiber impingement angle can be influenced in such a waythat the fibers can impinge onto the deposit belt at an angle of <90°.Consequently, even at high speeds of the guided fibers, a gentle andcareful depositing of the fibers on the deposit belt is achieved. Thekinetic energy accompanying the impingement of the fibers canadvantageously be included in the formation of the nonwoven. Moreover,the nonwoven acquires an essential uniform thick structure over theentire width of the deposit belt, without being damaged in the shapinggap between the deposit belt and the roller.

In order to allow the entry of the fiber stream into the open fiberentry gap without substantial air swirls, the development of theapparatus according to the invention is preferably used in which theguide member arranged on the belt inlet side is formed by a secondrotatably mounted roller which is held in contact with the deposit belt.Moreover, in this case, essentially wear-free sealing off with respectto surrounding influences can be generated on the deposit belt.

The guidance of the fibers within the guide segment and the depositingof the fibers in the lower region of the guide segment can be influencedin a desirable way by virtue of the development according to theinvention of the apparatus, in such a way that at least one of therollers has a perforated roller casing which is connected inside it to apressure chamber formed. By the pressure chamber being connected to apressure source or to suction extraction, additional air flows can begenerated within the guide segment. In this case, for example, pulsatingcompressed air variations within the pressure chamber can also beformed, so that special effects in the depositing of the nonwoven aregenerated.

The drive of the rollers preferably takes place by means of theconveying movement of the deposit belt, so that the rollers are held infrictional contact with the deposit belt. It is also possible, however,to assign at least one electric drive to the rollers.

The development of the apparatus according to the invention, in which atleast one of the rollers is assigned a ferromagnetic means whichcooperates with a magnet, preferably an electromagnet, arranged on anunderside of the deposit belt, in such a way that a pressure force actsbetween the roller and the deposit belt, is particularly advantageous inthe formation of a shaping gap between the roller and the deposit belt.Fine adjustment can thereby be carried out, so that a pressure forceoptimal in each case acts between the roller and the deposit belt as afunction of the filament strength of the fibers and of the weight perunit area of the nonwoven. Moreover, influencing the pressure forcebetween the roller and the deposit belt allows an optimal sealingfunction with respect to the surroundings, so that, for example, asucking in of extraneous air or the generation of air vortices at thesealing points is avoided.

Since apparatuses of this type are conventionally used for theproduction of different nonwovens, the development of the inventionleads to particular flexibility in which the guide member arranged onthe wall exit side or the deposit belt is assigned a height adjustmentdevice, by means of which a shaping gap formed between the guide memberand the deposit belt can be changed. In addition, a further optimizationfor the guidance and depositing of the fibers is afforded in that, tochange the guide segment formed between the guide members, at least oneof the guide members is held so as to be adjustable transversely withrespect to the suction nozzle.

In order to receive and discharge continuously the air quantity suppliedthrough the suction nozzle, the deposit belt has formed below it anadjustable suction port, by means of which a suction extraction deviceis connected to the underside of the deposit belt. In this case, thesuction port can be varied in its size between two cover plates helddisplaceably with respect to one another, so that, depending on thedepositing of the fibers, an optimized and uniform reception anddischarge of the conveying fluid take place.

A further improvement in the flexibility of the apparatus according tothe invention is afforded in that the guide members and the deposit beltare held on a lifting table which is movable between the take-up nozzleand the deposit belt in order to change a deposit height. By the guidemembers being tied up to the deposit belt, the entire free space betweenthe guide members and the take-up nozzle is available for adjustment.Furthermore, the take-up nozzle could likewise be designed to beadjustable in height.

Moreover, it is proposed that the outlet orifice of the take-up nozzlebe assigned at least one conveying means which is held at a distancefrom the guide members below the take-up nozzle. Further fiber guidancerelevant for the formation of the nonwoven can consequently be set.

The method according to the invention for depositing a multiplicity offibers to form a nonwoven combines the particular advantages of an opensystem, in which the fiber stream is blown directly into a free space,with a controlled and reproducible and also reliable depositing of thefibers to form a nonwoven. Surrounding influences caused, for example,by extraneous air are reduced to a minimum during depositing in spite ofthe open system.

The development of the method according to the invention in which thefibers are shaped to form the nonwoven by means of a pressure forceacting between a rotating roller and the deposit belt constitutes aparticularly advantageous method variant in which, on the one hand, ahigh sealing action of the guide segment is generated and, on the otherhand, nonwoven formation with an essentially constant nonwoven thicknessis generated without damage to the nonwoven. It proved particularlyadvantageous if the pressure force between the roller and the depositbelt is generated by means of a controllable electromagnet. Optimizedpressure forces can thus be set, depending on the filament cross sectionand nonwoven strength.

The apparatus according to the invention having the features accordingto one embodiment constitutes an advantageous design for generating bymagnetic means a pressure force acting between a roller and a depositbelt.

For this purpose, preferably, the magnet is of beam-shaped design and isarranged on an underside of the deposit belt. The magnetically conveyingmeans cooperating with the magnet are assigned to the roller, so that anattraction force determined by the magnet acts on the roller. Such adesign has the advantage, moreover, that the roller assumes anessentially unchanged position on the deposit belt.

The ferromagnetic means may in this case be formed directly by a rollercasing or, alternatively, by an iron roll which is arranged freelyrotatably inside the roller.

In order to obtain optimized sealing off of the deposit region both onthe exit side and on the inlet side of the deposit belt, preferably asecond roller is also held freely rotatably in contact with the depositbelt on the inflow side of the take-up nozzle, said second roller havinga ferromagnetic means and cooperating with a second magnet on theunderside of the deposit belt.

So that the pressure forces between the roller and the deposit belt canbe influenced, particularly for shaping the nonwoven, the magnet ispreferably formed by a controllable electromagnet, so that, by currentbeing applied to the electromotor, the intensity and therefore themagnitude of the pressure force can be varied.

The apparatus according to the invention and the method according to theinvention are distinguished by a stable and reproducible depositing ofthe fibers to form a nonwoven, high spinning and production speeds beingpossible. In this case, any desired setting can be carried out as afunction of the fiber type, fiber material and nonwoven requirement.There is also the possibility of carrying out the settings by means ofcontrollable actuators which, for example, are activated in an automatedmanner by means of a control device according to the stipulation ofprocess or product parameters.

BRIEF DESCRIPTION OF THE DRAWINGS

The apparatus according to the invention and the method according to theinvention are described in more detail below by means of some exemplaryembodiments, with reference to the accompanying figures in which:

FIG. 1 illustrates diagrammatically a view of a first exemplaryembodiment of the apparatus according to the invention;

FIG. 2 illustrates diagrammatically a cross-sectional view of a furtherexemplary embodiment of the apparatus according to the invention:

FIG. 3 illustrate diagrammatically a cross-sectional view of a furtherexemplary embodiment of the apparatus according to the invention; and

FIG. 4 illustrates diagrammatically a cross-sectional view of a furtherexemplary embodiment of the apparatus according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows diagrammatically a first exemplary embodiment of theapparatus according to the invention for depositing synthetic fibers toform a nonwoven and for carrying out the method according to theinvention.

The exemplary embodiment according to FIG. 1 shows a parallelepipedaltake-up nozzle 1 which is arranged in the usual way below a spinningdevice. Take-up nozzles of this type are generally known and areexplained in more detail, for example, in U.S. Pat. No. 6,183,684 B1. Tothat extent, reference is made to the publication mentioned and only theessential components are mentioned below.

The take-up nozzle 1 has a middle conveying duct 5 which is delimited ona top side of the take-up nozzle 1 by a fiber inlet 2 and on theunderside of the take-up nozzle 1 by a fiber outlet 3. The conveyingduct 5 is of slit-shaped design and extends essentially over the entirelength of the parallelepipedal take-up nozzle 1. On the longitudinalsides of the conveying duct 5, a plurality of fluid inlets, notillustrated here, are formed, which are connected to a fluid connection4. By means of the fluid connection 4, a conveying fluid is suppliedwhich has an excess pressure with respect to the atmosphere in theconveying duct 5.

The take-up nozzle 1 is arranged at a distance above a deposit belt 6.The deposit belt 6 has a belt width which extends over the entire lengthof the take-up nozzle 1. The deposit belt 6 is preferably guided as anendless belt via a plurality of conveying rolls and is driven so as tobe directed transversely with respect to the longitudinal side of thetake-up up nozzle 1. The deposit belt 6 therefore moves continuously ina guidance direction which is identified in the figure by an arrow. Thedeposit belt 6 is of air-permeable design, a suction extraction device31 being arranged on the underside of the deposit belt 6 in a depositregion formed vertically below the take-up nozzle 1.

In the region between the take-up nozzle 1 and the deposit belt 6, atravel is formed which is divided into a free space 17 formed directlybelow the take-up nozzle 1 and a guide segment 9 assigned to the depositbelt 6. The guide segment 9 is formed by the guide members 7.1 and 7.2which on a top side form, opposite the take-up nozzle 1, a fiber entrygap 8. For this purpose, the guide member 7.1 is arranged on a belt exitside 10 and the guide member 7.2 is arranged on the opposite belt inletside 11. In this case, the guide members 7.1 and 7.2 are formed in eachcase by a roller 12.1 and 12.2 held so as to be rotatably mounted. Theroller 12.1 on the belt exit side 10 and the roller 12.2 on the beltinlet side 11 are in each case in frictional contact with the depositbelt 6, so that the rotational movement of the rollers 12.1 and 12.2 isgenerated by friction by means of the conveying movement of the depositbelt 6. The roller 12.2 in this case bears directly against the surfaceof the deposit belt 6 or on a coating material. The roller 12.1 on thebelt exit side 10 forms with the top side of the deposit belt 6 ashaping gap 19 by means of which a nonwoven 21 is deposited and shaped.

The fiber entry gap 8 formed on the top side of the rollers 12.1 and12.2 is of essentially funnel-shaped design with respect to the freespace 17 due to the roller casings of the rollers 12.1 and 12.2. Theinterspace between the rollers 12.1 and 12.2 forms the guide segment 9in which the fiber stream blown in via the fiber entry gap 8 is guidedfor depositing onto the deposit belt 6. The guide segment 9 extends asfar as the top side of the deposit belt 6, the rollers 12.1 and 12.2 ineach case providing shielding with respect to the surroundings. Owing tothe direct frictional contact between the rollers 12.1 and 12.2 and thedeposit belt 6 and also the nonwoven surface of the nonwoven 21, sealingoff with respect to extraneous air is achieved.

The rollers 12.1 and 12.2 have in each case a perforated roller casing13 which is gas-permeable. Inside the rollers 12.1 and 12.2 is providedin each case a pressure chamber which is connected to a suction source16 or to a pressure source 18 via an air connection 15. In the exemplaryembodiment according to FIG. 1, the inner pressure chamber 14 of theroller 12.2 is coupled to the suction source 16. As a result, a uniformsuction action is generated on the roller casing 13 and leads to thedeflection and guidance of the fibers 20 within the guide segment 9. Thedeflection of the fibers 20 within the guide segment 9 is also increasedin that the pressure chamber of the roller 12.2 is coupled to a pressuresource 18. A uniform blowing flow can consequently be generated on theroller casing 13 of the roller 12.2.

During operation, a conveying fluid is supplied to the take-up nozzle 1.The conveying fluid used is preferably compressed air from a compressedair source, which flows into the conveying duct 5 with an excesspressure in the range of 0.1 to 5 bar, preferably in a range of 0.5 to 3bar excess pressure. As a result, the fiber strands 20 threaded into theconveying duct 5 via the fiber inlet 2 are taken up continuously from aspinning device, not illustrated here. In the spinning device, thefibers are melt-spun beforehand from a polymer material in anarrangement in the form of a row and are subsequently cooled. Within theconveying duct 5, the fiber strands 20 are accelerated by the conveyingfluid and are blown out jointly through the fiber outlet 3 as a fiberstream into the free space 17. The fiber stream which is composed of thefibers and the conveying fluid is in this case blown perpendicularlythrough the fiber outlet 3 in the direction of the deposit belt 6. Afterrunning through the free space 17, the fiber stream, together with thefiber strands 20, is blown into the fiber entry gap 8 formed by theguide members 7.1 and 7.2. Owing to the shape and configuration of theguide segment 9 and of the guide members 7.1 and 7.2, the fiber streamis guided in the direction of the deposit belt 6. Within the guidesegment 9, the fiber strands 20 impinge onto the deposit belt 6 at animpingement angle desired by the fiber stream being influenced and onthe surface of the deposit belt 6 form the nonwoven 21 which isdischarged continuously in the conveying direction by the deposit belt6. The suction flow generated on the roller 12.1 on the belt exit side10 causes a deflection of the fiber stream, so that the fiber strands 20impinge onto the deposit belt 6 at an impingement angle of <90°. In thiscase, a particularly careful depositing of the fibers takes place, sothat, even at high fiber speeds in the range 3500 m/min. to 8000 m/min.,no intensive catching between the surface of the deposit belt 6 and theindividual fibers 20 occurs. Moreover, the shaping gap 19 set by theroller 12.1 and the deposit belt 6 will cause the nonwoven 21 to acquirea nonwoven thickness which is essentially constant over the entire beltwidth. Damage to the nonwoven surface is ruled out on account of therotational movement of the roller 12.1.

The apparatus according to the invention and the method according to theinvention thus allow a uniform reproducible depositing of a nonwovenwhich can take place in a controllable way even at high fiber speeds. Inthis case, on the one hand, the advantages of the high draft, which areknown from the blowing of the fiber stream out into a free space, andalso the deposit mechanisms known per se only in closed systems areadvantageously combined by virtue of the invention. In spite of thereservation that air swirls occur at the transition between the freespace and the guide segment, it was possible, surprisingly, to generatehighly uniform and relatively smooth fiber stream profiles. Inparticular, configuring the guide members as rollers afforded a verygentle transition of the fiber stream out of the free space to the guidesegment.

FIG. 2 shows a further exemplary embodiment of the apparatus accordingto the invention. The exemplary embodiment according to FIG. 2 isessentially identical to the exemplary embodiment described above, andtherefore reference is made to the abovementioned description and onlythe differences are explained below.

In the exemplary embodiment, illustrated in FIG. 2, of the apparatusaccording to the invention, the guide members 7.1 and 7.2 assigned tothe deposit belt 6 are formed on the belt exit side 10 by a roller 12.1and on the belt inlet side 11 by an actuating wall 27. The actuatingwall 27 has in the lower region a flexible sealing lip 32 which bearswith a free end against the surface of the deposit belt 6 or of acoating material. The actuating wall 27 is held pivotably on a carrier28, the pivoting movement of the actuating wall 27 being implementableby means of an actuator 29. The guide member 7.1 arranged on theopposite wall exit side 10 is formed by the roller 12.1 which isdesigned essentially identically to the roller shown in FIG. 1. Theroller 12.1 is mounted rotatably on a bearing carrier 25. The bearingcarrier 25 is held via a holder 26, the bearing carrier 25 beingdesigned to be adjustable both vertically and horizontally on the holder26. Thus, on the one hand, the size of the shaping gap 19 between thedeposit belt 6 and the roller 12.1 can be varied and, on the other hand,the guide segment 9 between the actuating wall 27 and the roller 12.1can be varied.

A conveying means 33.1 and 33.2 is arranged in each case on each side ofthe take-up nozzle 1 directly on the side of the fiber outlet 3. Theconveying means 33.1 and 33.2 are in this case formed by pivotable guidebattens which are held pivotably on the underside of the take-up nozzle.By the conveying means 33.1 and 33.2 arranged on the outlet side of thetake-up nozzle 1, additional flow variations of the fiber stream can begenerated, which influence both entry into the fiber entry gap 8 and thedepositing of the fiber strands 20.

For discharge and for assisting the depositing of the fibers for forminga nonwoven, a suction extraction device 31 is arranged on the undersideof the deposit belt 6. In this case, the suction extraction action ofthe suction extraction device 31 is limited to the deposit region of theguide segment 9. The suction extraction device 31 has an adjustablesuction port 34 which is assigned directly to the deposit region on thedeposit belt 6. The suction port 34 is in this case formed between twodisplaceably arranged cover plates 35.1 and 35.2. Each of the coverplates 35.1 and 35.2 can be displaced horizontally in relation to oneanother.

In the exemplary embodiment illustrated in FIG. 2, the pressure chamber14 within the roller 12.2 is likewise connected to a suction source, sothat a suction flow prevails on the roller casing 13. A deflection ofthe fiber stream in the direction of the roller 12.1 can consequently begenerated, so that a gentle depositing of the fibers, even at very highfiber speeds, occurs.

FIG. 3 illustrates diagrammatically a cross-sectional view of a furtherexemplary embodiment of the apparatus according to the invention. Theset-up and functioning of the exemplary embodiment are essentiallyidentical to the exemplary embodiment according to FIG. 1, and thereforereference is made to the abovementioned description and only thedifferences are explained at this juncture.

In the exemplary embodiment, illustrated in FIG. 3, of the apparatusaccording to the invention, the guide members 7.1 and 7.2 assigned tothe deposit belt 6 for forming the guide segment 9 are formed in eachcase by a rotatable roller 12.1 and 12.2. Each of the rollers 12.1 and12.2 is in this case held by a bearing carrier 25 and a holder 26. Thebearing carrier 25 is in each case designed so as to be adjustable inthe conveying direction of the deposit belt 6 and opposite to theconveying direction of the deposit belt 6 on the holder 26. The bearingcarrier 25 of the roller 12.1 is additionally designed to be adjustablevertically for setting a shaping gap 19 between the roller 12.1 and thedeposit belt 6.

In order to obtain reliable frictional contact between the rollers 12.1and the deposit belt 6 and also the roller 12.2 and the deposit belt 6,each roller 12.1 and 12.2 is assigned in each case ferromagnetic means22 and a magnet 23. The design of the ferromagnetic means 22 and of themagnet 23 is identical for each roller 12.1 and 12.2, and therefore thedesign is explained in more detail by the example of the roller 12.1.The ferromagnetic means 22 is formed directly by the roller casing 13which consists of a ferromagnetic material. On the underside of thedeposit belt 6 is provided a magnet carrier 36 which extends essentiallyover the entire belt width and which carries the beam-shaped magnet 23.The magnet 23 is preferably formed by an electromagnet which, by currentbeing applied, exerts magnetization and consequently an attraction forcewith respect to the roller casing 13. The roller casing 13 of the roller12.1 is thus attracted in the direction of the deposit belt 6. In thiscase, a pressure force acting between the roller 12.1 and the depositbelt 6 builds up and acts directly on the nonwoven 21 in the shaping gap19. The application of the current to the electromagnet 23 is in thiscase selected in such a way that, on the one hand, sufficient sealingoff with respect to the inflow instances of extraneous air is obtainedand, on the other hand, no damage to the nonwoven 21 occurs.

On the opposite side, the roller 12.2 is attracted in the same way bymeans of a casing 13 formed from ferromagnetic material and the secondmagnet 23 arranged on the underside of the deposit belt 6, so that theroller casing 13 is held directly against the surface of the depositbelt 6 and leads to a sealing off of the guide segment 9 between therollers 12.1 and 12.2.

In the exemplary embodiment illustrated in FIG. 3, the pressure chamber14 formed in the roller 12.1 is connected to a pressure source and thepressure chamber formed in the roller 12.2 is connected to a suctionsource. An essentially perpendicular depositing of the fiber strands 20on the deposit belt 6 is thus achieved.

In the free space 17, two conveying means 33.1 and 33.2 are assigneddirectly to the fiber outlet 3 of the take-up nozzle 1, the conveyingmeans 33.1 and 33.2 being formed in each case by freely rotatable rollswhich are designed to be adjustable in their position in and opposite tothe conveying direction of the deposit belt.

The function of the apparatus for forming the nonwoven, as illustratedin FIG. 3, is identical to the preceding exemplary embodiments, andtherefore no further description of this is given.

FIG. 4 shows a further alternative to the apparatus illustrated in FIG.3, the mount of the rollers 12.1 and 12.2 not being illustrated in anymore detail.

To fix the rollers 12.1 and 12.2, the ferromagnetic means 22 is formedin each case by an iron roll 37 which is arranged rotatably inside theroller 12.1 or the roller 12.2. By means of the magnet 23 arranged onthe underside of the deposit belt 6, the iron roll 37 is attracted inthe direction of the deposit belt 6 and leads to the reliable bearing ofthe roller 12.1 against the top side of the nonwoven 21 or to a reliablebearing of the roller 12.2 against the top side of the deposit belt 6.The magnet assigned to the roller 12.1 on the belt exit side 10 isdesigned as an electromagnet 23 which can be activated via a controlunit 38 and a control device 39. In this case, process data, such as,for example, fiber cross sections and weight per unit area or nonwoventhickness, can be preset for the control device 39. By means of a storedoptimization program, a current size is determined from the processparameters and is predetermined via the control unit 38 for theapplication of current to the electromagnet 23. The application ofcurrent to the electromagnet 23 leads to an attraction force andconsequently to a pressure force between the roller 12.1 and the depositbelt 6, said pressure force being adapted to the respective processparameters.

In the design, illustrated in FIG. 4, of the apparatus according to theinvention, the deposit belt 6 and the guide members 7.1 and 7.2 arearranged jointly on a lifting table 30. For this purpose, a conveyingroll 40 of the deposit belt 6 is supported on the lifting table 30 via aroll carrier 41. The lifting table 30 is designed to be adjustable inheight in the direction of the take-up nozzle 1, so that the depositheight which extends between the pick-up nozzle 1 and the deposit belt 6can be varied. In this case, the travel formed by the free space 17 canbe utilized for adjusting the deposit height. Usually, in the apparatusaccording to the invention, deposit heights in the range of 50 to 500 mmare set. Alternatively, the take-up nozzle could be designed to beadjustable in height.

The exemplary embodiments, illustrated in FIG. 1 to 4, of the apparatusaccording to the invention for carrying out the method according to theinvention are given as examples in terms of the set-up and arrangementof the guide members. It is essential in this case that the fibers,shortly before they impinge on the deposit belt, are guided by a guidesegment closed with respect to the deposit belt. In particular, in thiscase, guide members are suitable which allow a stable and reproducibleguidance and depositing of the fiber strands.

1. An apparatus for depositing synthetic fibers to form a nonwoven, saidapparatus comprising: a take-up nozzle; a deposit belt which is arrangedbelow the take-up nozzle and which is driven so as to be directedtransversely with respect to a longitudinal side of the take-up nozzle;and guide members arranged in a free space formed between the take-upnozzle and the deposit belt, wherein one of the guide members isarranged on a belt exit side and an opposite guide member is arranged ona belt inlet side, and wherein the guide members form, at a distancefrom the take-up nozzle, an open fiber entry gap to a guide segmentformed between the guide members, which guide segment extends betweenthe guide members as far as the deposit belt.
 2. The apparatus asclaimed in claim 1, wherein the guide member arranged on the belt exitside is formed by a rotatably mounted roller which with the deposit beltforms a shaping gap for the nonwoven.
 3. The apparatus as claimed inclaim 2, wherein the guide member arranged on the belt inlet side isformed by a second rotatably mounted roller which is held in contactwith the deposit belt.
 4. The apparatus as claimed in claim 3, whereinat least one of the rollers has a perforated roller casing, and whereinthe roller casing is connected to a pressure chamber formed inside theroller.
 5. The apparatus as claimed in claim 4, wherein the pressurechamber within the roller is connected to a compressed air source or tosuction extraction.
 6. The apparatus as claimed in claim 3, wherein atleast one of the rollers is held in frictional contact with the depositbelt and is configured to be driven by means of a conveying movement ofthe deposit belt.
 7. The apparatus as claimed in claim 3, wherein atleast one of the rollers is coupled to an electric drive.
 8. Theapparatus as claimed in claim 3, wherein at least one of the rollers isassigned a ferromagnetic means which cooperates with a magnet arrangedon an underside of the deposit belt, in such a way that a pressure forceacts between the roller and the deposit belt.
 9. The apparatus asclaimed in claim 8, wherein the magnet comprises an electromagnet. 10.The apparatus as claimed in claim 1, wherein the guide member arrangedon the belt exit side or the deposit belt is assigned an adjustmentdevice, by means of which a shaping gap formed between the guide memberand the deposit belt can be changed.
 11. The apparatus as claimed inclaim 1, wherein, to change the guide segment formed between the guidemembers, at least one of the guide members is held so as to beadjustable transversely with respect to the take-up nozzle.
 12. Theapparatus as claimed in claim 1, wherein an adjustable suction port isformed, below the deposit belt by means of which suction port a suctionextraction device is connected to the underside of the deposit belt. 13.The apparatus as claimed in claim 12, wherein the suction port is formedbetween two cover plates held so as to be displaceable in relation toone another.
 14. The apparatus as claimed in claim 1, wherein the guidemembers and the deposit belt are held on a lifting table which ismovable between the take-up nozzle and the deposit belt in order tochange a deposit height.
 15. The apparatus as claimed in claim 1,wherein the fiber outlet of the take-up nozzle is assigned at least oneconveying means which is held at a distance from the guide members belowthe take-up nozzle.
 16. A method for depositing a multiplicity of fibersto form a nonwoven, said method comprising: blowing the fibers onto adriven deposit belt in an arrangement in the form of a row, wherein thefibers, before being deposited onto the deposit belt, are blown into aguide segment formed by cooperating guide members and are subsequentlydeposited at the end of the guide segment to form the nonwoven.
 17. Themethod as claimed in claim 16, wherein the fibers are shaped to form thenonwoven by means of a pressure force acting between a rotating rollerand the deposit belt.
 18. The method as claimed in claim 17, wherein thepressure force between the roller and the deposit belt is generated bymeans of a controllable electromagnet.
 19. The method as claimed inclaim 18, wherein the application of current to the electromagnet iscontrolled as a function of the fiber cross section and of a weight perunit area of the nonwoven.
 20. An apparatus for depositing syntheticfibers to form a nonwoven, said apparatus comprising: a take-up nozzle;a deposit belt which is arranged below the take-up nozzle and which isdriven so as to be directed transversely with respect to thelongitudinal side of the take-up nozzle; and a plurality of guidemembers arranged between the take-up nozzle and the deposit belt, one ofthe guide members on a belt exit side being a freely rotatable rollerwhich with the deposit belt forms a shaping gap, wherein ferromagneticmeans with a magnet are provided, by which a pressure force between theroller and the deposit belt can be generated.
 21. The apparatus asclaimed in claim 20, wherein the magnet is of beam-shaped design and isarranged on an underside of the deposit belt, and wherein theferromagnetic means is assigned to the roller.
 22. The apparatus asclaimed in claim 21, wherein the ferromagnetic means is formed by aroller casing.
 23. The apparatus as claimed in claim 21, wherein theferromagnetic means is formed by an iron roll which is arranged freelyrotatably inside the roller.
 24. The apparatus as claimed in one ofclaim 20, wherein, on an inflow side of the take-up nozzle, a secondroller is held freely rotatably in contact with the deposit belt, andwherein further ferromagnetic means with a second magnet is provided, bywhich the second roller s pressed against the deposit belt.
 25. Theapparatus as claimed in claim 24, wherein the second magnet is ofbeam-shaped design and is arranged on an underside of the deposit belt,and wherein the ferromagnetic means is assigned to the second roller.26. The apparatus as claimed in claim 20, wherein the magnet is formedby a controllable electromagnet.